New Copper-gold discoveries at the Pebble project in Alaska: production is still years away, but much preliminary work is being done to mine this mineral-rich area.

• Author: Colby, Kent
• Position: Alaska's vast gold and copper resources

Alaska is home to one of the world's largest gold and copper resources. That's what company officials of Northern Dynasty Minerals Ltd. claim. And to back up that claim, the company invested a bit more than $2.5 million last year-and will spend more than that to further development this year.

Perhaps you have heard of the Pebble-gold-copper discovery in Southwest Alaska near Iliamna? Even though gold and copper are the deposit's primary commodities, it also contains molybdenum and other minerals. The Pebble project is part of an Alaska porphyry belt, located on state-owned land just 15 miles from Iliamna and within the bounds of the Bristol Bay Native Corp. The mineral-rich porphyry intrusion rests in the rolling tundra 235 miles southwest of Anchorage.

In the past year, activities by Northern Dynasty have hyped interest in mineral exploration in the area. A gold-copper discovery in the early 1980s was made through initial exploration by Cominco, now Teck Cominco Ltd. Targeting gold-bearing quartz veins in the area, Cominco, in the late 1980s, was attracted to the area's moderate terrain and easy access just 60 miles from the coastal waters of Alaska's Cook Inlet. Originally targeting gold-bearing quartz veins in the area led to a major gold-copper discovery. Cominco continued drilling up through 1997, when metallurgical tests indicated recovery rates up to 94 percent for copper, 84 percent for gold and 78 percent for molybdenum. However, even with those numbers, and the geochemical results indicating additional gold and copper to be found, success appeared marginal. Last April, the Gold Newsletter reported: "...and remember, the Pebble Deposit is on the verge of economic viability."

ECONOMICALLY VIABILITY

Porphyry deposits are the world's most important source of copper and molybdenum and account for an increasing proportion of low-cost gold production.

In 2001, the Hunter-Dickinson Group acquired options to purchase the claims and assigned the project to Northern Dynasty. Last year, Northern Dynasty undertook an aggressive diamond drilling program that demonstrated that the Pebble sulphide system hosts multiple, large-scale deposits. This drilling on the Pebble deposit and the exploration lands around the Pebble deposit yielded new porphyry, skarn and vein discoveries. Detailed studies of the Pebble porphyry deposit itself indicated it is one of the world's largest gold and copper resources, containing 13.1 million ounces of gold and 6.8...